<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<title></title>
	<style type="text/css">
		div{
			width: 0;
			height: 0;
/*			background: yellowgreen;*/
			border:200px solid;
			border-color: skyblue white skyblue white;
			margin: 0 auto;
			border-radius: 50%; 
            /*	旋转		*/
			transform: rotate(-45deg);
		}
	</style>
</head>
<body>
	<div></div>
</body>
</html>